Thank you. I will view it.
I thought if the wheel is kept as close in Under the fenders like stock as possible you’re good. It’s when you start pushing out you have issues? Is there calculate the changes you make? This is a very confusing subjectThis is a good topic for discussion, best to keep scrub radius as close to stock as possible for best on-road manners. Engineers design the steering geometry for best steering response for safe daily driving. If you start pushing the scrub radius far from where it's designed to function your road handing and safety can come into play. Now what would be the point where it starts to take a serious dive? That's the million dollar question
I'm not messing w/ my suspension as far as a lift and trying to keep my offset (and scrub radius) as close to stock as I find feasible, I've done the serious altered suspension and higher offset wheels, don't want to go down that path this time
Boy this is way beyond my conception. Thanks for the article. Hubby is better at understanding this stuff.An interesting point that I haven't seen mentioned is that the scrub radius also changes with tire diameter. A wheel with less backspace and larger tires could be near OEM spec.
Here's a really in depth suspension article where I stole this image from: https://motoiq.com/the-ultimate-han...your-caster-king-pin-inclination-and-scrub/4/
I agree, but would also like to point out that there are at least 3 different "stock" scrub radius values with the JL as the Sport, Sahara, & Rubicon all have different sized tires. I think that it scrub radius should be looked at as an acceptable range, and that exact OEM measurements are not ultimately necessary. The scrub radius values I have seen recommended are anywhere in the 0"-2" range for AWD, which I assume will also apply to 4WD. RWD only is 0"-3".
I think that it should also be noted that suspension lift (with a solid axle) does not have any effect on scrub radius (unless you count the minor changes from altering caster at the same time).
To be honest, it is a tough subject for me also. Here's the important bits I found from the article I posted above:
From the way I understand it: if you consider just the drivers front tire encountering an obstacle at the direct center of the tire, with 0 scrub there will be no left/right turning reaction. With more scrub radius, the same obstacle will cause a lever-arm effect on that tire, which would then want to turn the tire counterclockwise. With a smooth surface or uniform left & right bumps, this is not noticed as the forces would cancel each other out.
Interesting. The JL Rubicon axles are wider than the jk. I guess maybe that throws the numbers off a bit. I don’t know. So for a 35 inch tire you would have to deduct 5.4 mm? I’m running now -12 offset do that’s way, way different
Axle width actually isn't a component when strictly looking at scrub radius. It is all about the relation of the steering axis ground intersection point vs. the center of the tire's contact patch.
Yes, that is correct. To have close to OEM scrub radius with 35" tires on a Rubicon, you would need wheels with offset close to 38.6mm. With -10 offset wheels, you have somewhere around 1.91" more scrub radius than the OEM Rubicon.
I dunno how feasible it is to have a 38.6 mm offset with 35s. Maybe those who use the stock wheels can achieve that. But certainly shows me that the high negative offsets are asking for trouble.
Didn't mean to lump a lift kit w/ scrub radius, I was just saying that I'm keeping my Jeep @ Stock height so I won't introduce new sets of issues, AND keeping my scrub radius as close to stock as I can w/ my 8.5 +10 on 295/70s. It's going to be off, but not overly so, and this wheel I liked best in the +10. Ideally I could go in another 15-20 mm from the room I have at lock to lock, so if they had them in a +25 I think I'd have gone that route.